The present invention relates to a slit nozzle, and more particularly a slit nozzle useful in an apparatus and method for processing wafer-shaped articles, such as semiconductor wafers.
During the manufacture of semiconductor devices the surfaces of the wafers from which the devices are formed go through various processes, a number of which involve dispensing process liquids and/or rinsing and cleaning liquids onto the wafer surface. Conventional nozzles dispense liquids through a circular outlet opening, such that the stream of liquid impinging on the wafer surface is generally cylindrical.
However, for certain processes it is desired to dispense the process liquid in more of a curtain shape, as is produced when the nozzle has a slit-shaped outlet opening.
Conventional slit nozzles are not well suited to use in liquid dispensers of apparatus for processing semiconductor wafers, however, because such apparatus have exacting requirements with respect to how quickly the dispensing of liquid commences after turning on the liquid supply, as well as how quickly and completely the liquid flow can be halted upon completion of a process, without residual drops of liquid falling on to the wafer surface. Moreover, the nozzle performance in each of these areas must be highly reproducible from one process iteration to the next.